Makers of Turning Cutting Tools Innovate in Tough Times

Makers of cutting tools for turning applications are having to innovate and improve their products amid tough times—the falloff in demand for tubing for the oil & gas industry, a key market. That means, among things, they must continue to up their game in finding ways to cut hard-to-machine materials such as Inconel and titanium while still working on tools—despite the decrease in demand—that produce better tubing that can be used to drill deeper in more isolated places.

“As these materials are pushed to be stronger and more heat resistant, due to the depths they are going, the tube gets harder and harder to machine,” said John Winter, product specialist-turning of Sandvik Coromant (Fair Lawn, NJ), which has come out with Inveio, a new coating technology for steel turning and cast iron turning grades. “So the need for new cutting methods, new cutting material and new coatings is a must moving forward.”

“The high strength and heat resistance of these alloys plays a huge role in cutting tool selection,” said Eric Jenkins, indexable tooling technical manager of Kyocera Precision Tools Inc. (Hendersonville, NC), said in an e-mail. “Many factors have to be considered, including such things as the shape of the workpiece, the amount of stock removal and/or the presence of scale.”

With nickel-based forgings, he said, “Customers can choose between different insert geometries as well as different categories of ceramics and carbides, depending on the specific details of the application.”

‘High-Temp Alloys’

“With the development of new materials like high-temp alloys, cutting tool manufacturers also have to develop new grades and geometries to machine and process these materials efficiently while providing long tool life,” said David Essex, turning product manager of Tungaloy America Inc. (Arlington Heights, IL).

What’s more, all companies with ties to the energy sector are going to be called upon to do more.

“Rapid changes in price, such as the halving of the oil benchmark between 2014 and 2015, naturally bring into focus the need for oil companies and their suppliers to reduce costs to maintain viable returns,” Paul Markwell, vice president of upstream oil and gas consulting and research at IHS Energy, said in a statement.

“Technology helps on two fronts,” he said. “The first is in raising short-term production, the key denominator in the cost-per-barrel equation. The other involves attacking capital costs and operating expenses head on. Both place an emphasis on efficiency.”

Makers of cutting tools are looking to keep improving their offerings even while one of the drivers of their business—oil exploration—slackens.

That means confronting various issues.

Tougher Materials

First, materials. “In general we can say: the tougher the material, the more difficult the machining, as the chemical makeup of the material creates higher cutting forces,” said Sandvik Coromant’s Winter.

“For example, with chip control, you might get long stringy chips wrapping around the parts and tools,” he said. “High cutting speeds can cause sudden chipping, fracture of the cutting edge and built-up edge. Some alloys also work-harden easily, leading to diffusion-type wear and subsequently to excessive burr formations that make following operations more difficult.”

Added Tungaloy’s Essex: “Customers come to us to help them solve manufacturing problems in processing difficult materials and we have to make sure our products provide those solutions.

“Competition in the market requires that we stay on the leading edge,” he said. “Our focus is on developing new grades and geometries for accelerated machining.”

Chip Control

The second issue to contront is evacuating chips resulting from cutting. “Turning encompasses both internal and external machining scenarios,” said Kyocera’s Jenkins. “In both cases, proper chip control is critical to prevent machine downtime for the removal of improperly cut chips. In addition, poor chip control can cause premature wear and failure of the insert, bad surface finishes, and can even pose a threat to operators who are forced to manually deal with the chips themselves.”

“Chip control and chip evacuation are key components to providing optimum tool life, superior surface finishes and process reliability,” said Tungaloy’s Essex. “Improper chip evacuation or chip control in boring applications can damage the edges of your insert prematurely from chips packing inside the part. Not only can the tooling be damaged but you run the risk of also damaging the expensive parts being machined.”

“Tool life is the product of cutting intensity, materials processed, machine stability and, of course, piece parts produced,” Preben Hansen, president of Heimatec Inc. (Prospect Heights, IL), said in a statement. “Two seemingly identical job shops can have vastly different tooling needs.”

Companies are looking to coatings and coolants for answers.

“As you go faster you create more heat” which will require “new cutting tool material with even higher heat resistance, coatings that react to the heat to allow higher cutting speeds, and the use of coolant, specifically high-pressure coolant and under coolant and the use of coolant in ways to reduce heat in the cutting zone,” Winter said.

“Insert coatings are constantly being developed to help prolong the life of the tool,” Jenkins said. “It is possible to economically manufacture indexable inserts with tighter tolerances than those found in previous generations of the same product. This combination is yielding inserts with great stability, meaning repeatable and consistent part counts, right out of the box.”

Also, he said, “The use of high-pressure coolant and the corresponding coolant-through holders will become more common in turning applications. Delivering high-pressure coolant through the proper area of the cutting zone will result in lower cutting temperatures and prolonged insert life. More customers will be considering high-pressure coolant as an option. Coating technology will continue to evolve, with the use of nano-coatings becoming increasingly more common. These advanced coatings provide more stable and consistent tool wear.”

‘Huge Leap’

“The newest tooling developed for turning and grooving applications is coolant-through holders that are designed to deliver coolant directly to the cutting edge of the insert,” Essex said. “Coolant-through external holders have created a huge leap in improving tool life and processing speeds. Coolant directed directly to the cutting edge from two directions provides added chip control capabilities.”

Essex added other changes may occur in the next five years.

“Machine tools with multiple axes for the ability to machine more complex geometries in the aerospace industry will be increasingly utilized,” he said. “Machines with higher accuracies and rigidity and better software will allow faster machine times.”

What follows is a look at some of the new products on the market.

Sandvik Coromant: The company’s markets include automotive, which had a much better year in 2015 thanks to vehicle production spurred by record US car and light-truck sales.

Sandvik Coromant’s newer offerings include Inveio, with new insert grades GC4325 (for steel turning) and GC3330 (for cast iron milling). The company also has the CB7015, intended for use in producing transmission parts. The company said the newer products coupled with existing ones permit high production at a low per-unit cost.

In March, Sandvik Coromant introduced its CoroTurn 300 turning holder for steel turning operations. The company said CoroTurn 300 has stable insert clamping and eight-edged inserts for chip control. CoroTurn also has high-precision over and under coolant.

Tungaloy America: The company’s Tungjet system features coolant through external toolholders for turning. The company said the retractable top jet provides better chip control and the jet from under the cutting edge boosts tool life and permits faster cutting speeds.

The company also offers TetraCut and EasyCut systems that provide coolant through the holders, directing coolant to the cutting edge, resulting in “adequate cooling for improved tool life and chip evacuation for deep grooving applications.”

The company has developed a new grade for high-temperature alloys, the AH8000 series. It also had a new grade for grooving in its TungCut product line, AH7025.

Kyocera Precision Tools: The company recently introduced MEGACOAT-NANO turning grade PR1535 for “stable machining of difficult-to-cut materials such as heat-resistant alloy, Inconel, titanium alloy, and stainless steel.” Kyocera said the MEGACOAT-NANO coating of PR1535 “protects against wear and fracture with its high hardness and superior oxidation resistance.”

Horn USA Inc. (Franklin, TN): The company’s newer products include an extension to its Supermini type 105 tool system, which performs tasks involving bore diameters between 0.2 and 6 mm. There are more than 1000 versions of the carbide insert that fit one toolholder.

The new type 105 carbide hard boring inserts can work in bore diameters of 4–5 mm and bore depths to 10, 15 and 20 mm in materials up to 66 HRC without utilizing CBN tips.

Heimatec: The company’s products include its U-Tec flexible adapted system on all right-angle heads in its line. Heimatec also offers a coolant-through feature on all of its current line products. It also offers a line of standard and custom angle heads.

Kennametal (Latrobe, PA): is offering its Beyond Evolution grooving and cutoff system. The company is marketing Beyond Evolution as providing tighter index tolerances and longer cutting depths. It has a design Kennmetal calls Triple V. The company said the design results in “high stability for deep grooving, face grooving, side turning and profiling.”